Studies: Benefits of HIV treatment interruptions still unclear

BY Advocate.com Editors

February 14 2003 1:00 AM ET

Research presented Wednesday at the 10th annual Conference on Retroviruses and Opportunistic Infections in Boston has failed to settle the question of whether treatment breaks are helpful for HIV-positive people, with new studies failing to reach any consensus, The Washington Post reports. The new research suggests that longer, more open-ended breaks may be better for patients than the presumably safer shorter breaks, but whether there is an overall benefit in terms of reduction of drug-resistant virus or a long-term boost to the immune system remains uncertain.

"It's a hodgepodge," said John W. Mellors, an AIDS physician at the University of Pittsburgh and one of the organizers of the retrovirus conference. "It's much more complicated than we think. The message is, people shouldn't be willy-nilly interrupting treatment."

A study conducted in Thailand compared three treatment approaches--ongoing treatment with three anti-HIV medications, treatment with three drugs on a week-on/week-off schedule, and treatment breaks that lasted as long as each study subject's T-cell count remained above a predetermined threshold. The patients in the latter group took anti-HIV drugs for only about one third of the yearlong study and were better able to maintain lower viral loads than those in the week-on/week-off group. But there were no long-term benefits seen in either group taking treatment breaks--mortality, complications, and quality-of-life measures were similar among all three groups.

A U.S. study examined whether short treatment breaks, during which HIV viral levels rebound, would be effective in priming the immune system to better fight HIV by repeatedly exposing it to surging viral levels then helping it to fight off the infection when the drugs are reintroduced. It was theorized that the immune system could thus be boosted to a point where all anti-HIV drugs could be permanently stopped. However, the research showed that seven rounds of eight weeks on/four weeks off treatment did not achieve this result and also did not help lower cholesterol and triglyceride levels that can climb during antiretroviral therapy. Worse yet, levels of drug-resistant virus climbed in all of the study subjects throughout the study, suggesting that short treatment breaks are more harmful than helpful.

A large-scale U.S. study based on the Thai research that examined long-term treatment interruptions guided by a patient's T-cell count will begin soon, researchers at the conference announced.